docs: def chain(self):
          """
          Add patterns chain, using configuration from this chain
  
          :return:
          :rtype:
          """
          # pylint: disable=protected-access
          chain = self.rebulk.chain(**self._kwargs)
          chain._defaults = dict(self._defaults)
          chain._regex_defaults = dict(self._regex_defaults)
          chain._functional_defaults = dict(self._functional_defaults)
          chain._string_defaults = dict(self._string_defaults)
          return chain